Male traits and herd reproductive capability in tropical beef cattle. 1. Experimental design and animal measures
B. M. Burns A B I , N. J. Corbet A C , D. H. Corbet A D , J. M. Crisp A E , B. K. Venus A F , D. J. Johnston A G , Y. Li A H , M. R. McGowan A E and R. G. Holroyd A D
+ Author Affiliations
- Author Affiliations
A Cooperative Research Centre for Beef Genetic Technologies, Armidale, NSW 2351, Australia.
B The University of Queensland, Centre for Animal Science, Queensland Alliance for Agriculture and Food Innovation, Rockhampton, Qld 4701, Australia.
C CSIRO Livestock Industries, Rockhampton, Qld 4701, Australia.
D Animal Science, Agri-Science Queensland, Department of Employment, Economic Development and Innovation (DEEDI), Rockhampton, Qld 4701, Australia.
E The University of Queensland, School of Veterinary Science, Gatton Campus, Gatton, Qld 4343, Australia.
F Animal Science, Agri-Science Queensland, DEEDI, Qld Biosciences Precinct, St Lucia, Qld 4072, Australia.
G Animal Genetics and Breeding Unit (AGBU), University of New England, Armidale, NSW 2351, Australia.
H CSIRO Livestock Industries, St Lucia, Qld 4067, Australia.
I Corresponding author. Email: b.burns@uq.edu.au
Animal Production Science 53(2) 87-100 https://doi.org/10.1071/AN12162
Submitted: 14 May 2012 Accepted: 23 July 2012 Published: 4 December 2012
Abstract
Research into the genetics of whole herd profitability has been a focus of the Beef Cooperative Research Centre for Beef Genetic Technologies over the past decade and it has been identified that measures of male reproduction may offer a potential indirect means of selecting for improved female reproduction. This paper describes the experimental design and provides a descriptive analysis of an array of male traits in Brahman and Tropical Composite genotypes managed under the medium to high stress, semi-extensive to extensive production systems of northern Australia. A total of 1639 Brahman and 2424 Tropical Composite bulls with known pedigrees, bred and raised in northern Australia, were evaluated for a comprehensive range of productive and reproductive traits. These included blood hormonal traits (luteinising hormone, inhibin and insulin-like growth factor-I); growth and carcass traits (liveweight, body condition score, ultrasound scanned 12–13th rib fat, rump P8 fat, eye muscle area and hip height); adaptation traits (flight time and rectal temperature); and a bull breeding soundness evaluation (leg and hoof conformation, sheath score, length of everted prepuce, penile anatomy, scrotal circumference, semen mass activity, sperm motility and sperm morphology). Large phenotypic variation was evident for most traits, with complete overlap between genotypes, indicating that there is likely to be a significant opportunity to improve bull fertility traits through management and bull selection.
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